This invention is directed to ostomy bags and more particularly to an ostomy bag with a novel multi-stage filter that resists contact contamination by semi-liquid waste collected in the bag.
Gases emitted from the stoma into an ostomy bag and gases that issue from waste material confined in the bag are usually evacuated through a deodorizing filter. A gas outlet is thus provided in the ostomy bag, normally adjacent the deodorizing filter to ensure that the outward flow of gas passes through the filter.
Most ostomy bags can generally be worn a few days before the deodorizing capability of the filter begins to lose effectiveness. The exhausted filter can then be replaced if the bag has provision for replaceable filters as in ostomy bags of U.S. Pat. No. 5,085,652. If there is no provision for filter replacement as in the ostomy bag of U.S. Pat. No. 5,074,851, the entire bag is disposed of and replaced when the filter is no longer an effective deodorizer.
If the deodorizing filter is inadvertently contaminated by contact with waste material that accumulates in the bag, it may be desirable to replace the disposable bag immediately. Waste material contact with a deodorizing filter can occur as a result of physical activity by the wearer that shifts the contents of the bag toward the deodorizing filter, especially if such waste material is of a liquid or semi-liquid consistency.
Contact of the deodorizing filter with semi-liquid waste material will often clog the filter, thereby preventing adequate deodorization and evacuation of waste gas. Whenever a filter is contaminated by contact with semi-liquid waste material and such contamination impedes the function of the filter, the filter or bag should be replaced as soon as possible. The need for accelerated replacement of deodorizing filters and/or ostomy bags because of contact contamination by waste is usually an inconvenience to the wearer.
Filter contamination from contact with semi-liquid waste also commonly occurs when an individual is asleep or reclining because the ostomy bag is in a relatively horizontal orientation. In such instances, gas pressure may build up in the bag because of the lowered rate of gas evacuation due to filter clog. Pressure release can thus occur through an undesirable break in the bag seal at the stoma. If the leak or seal break is not detected, it can result in the soiling of an individual's garments.
It is thus desirable to provide an ostomy bag with a multi-stage filter system that prevents semi-liquid waste material from contaminating a deodorizing element but does not inhibit evacuation of gaseous waste through the deodorizing element.